Construction of grinders for use in lathes or the like



E. RITZ, JR

April 3, 1934.

CONSTRUCTION OF GRINDERS FOR USE IN LATHES OR THE LIKE 2 Sheets-Sheet 1 Filed June 17, 1931 -Ejii jlji] A TTORNEYJ? E. RITZ, JR

April 3, 1934.

CONSTRUCTION OF GRINDERS FOR USE IN LATHES OR THE LIKE Filed June 17, 1931 2 Sheets-Sheet 2 INVENTOR.

ATTORNEYS Patented Apr. 3, 1934 UNITED STATES PATENT DFFICE CONSTRUCTION OF GRINDERS FOR USE IN LATHES OR THE LIKE Application June 17, 1931, Serial No. 545,037

2 Claims.

My invention is addressed to grinders of a character useful as a tool in a lathe for external or internal grinding, though capable of other applications; and it is particularly addressed. to

. grinders of the self-contained type, i. e. the type in which a motor or other prime mover and a grinding mechanism are built as a unit for use as such. 1 When such a grinder is used in connection with a lathe or other device, it is highly de sirable and sometimes necessary to be able to center the shaft of the grinder with reference to the head stock of the lathe. In an exemplary use of my invention, the lathe may be thought of as having a bed upon which there are ways for the guiding of the tool carriage, which slides longitudinally of the bed. A cross slide is mounted on the tool carriage, and usually upon an adjustable swivel which enables it to be set at a desired angle to the ways. The base plate of a grinder of the type to which my invention is'particulan Z the bed, it will take care of any horizontal component of a centering or adjusting motion. A vertical component of motion in the grinder shaft is desirable, not only for centering as above referred to, but also for other adjustments. It is ,usually not practicable to raise and lower the grinding machine bodily. An object of my invention, therefore, is to provide means whereby the grinding shaft of such an assembly as has been referred to, may have an adjusting motion in a 1 direction other than horizontal.

It has been pointed out that in the usual construction a motor rests upon the bed of a grinding machine. By raising of clearance in the lathe, it will substantially always be found necessary to locate the horizontal grinding shaft of the grinding machine below a horizontal plane passing through the motor shaft. Usually some form of belt drive is chosen. A vertical motion of the grinder shaft, while it would take care of the adidljustability which is desirable, would nevertheless vary the tension of the belt or drivingmeans, and thus seriously affect the perfcrmance of the device. The employment of automatic belt tighteners involves a number of disadvantages.

- The provision of means whereby the grinder shaft may be caused to move in an are about the motor shaft as a center will maintain the belt tension, but complicates the matter of adjustment and is likely to make for expense, or inii accuracy and instability. Another object of my invention, therefore, is the provision of simple mechanical means whereby a non-horizontal motion of the grinder shaft may be made for adjustment without varying the adjustment of the CO driving means.

These and other objects of my invention which will be apparent to those skilled in the art upon reading these specifications or will be pointed out hereinafter, I accomplish by that certain construction and arrangement of parts of which I shall now describe an exemplary embodiment, reference being had to the drawings, in which:

Figure 1 is an elevation of a grinder embodying my invention, and

Fig. -2 is an end elevation thereof.

I have shown a grinder having a base 1,which is attached, as by means of a clamp co-operating with the tool post 2, to the cross slide 3 of the lathe. The cross slide will be moved for horizontal motion upon the swiveled portion 4 of the carriage. An electric motor 5 is mounted on my base. This motor drives my grinder shaft through a belt 6, passing over the motor pulley '7, and a pulley 8 on the grind shaft. The grind shaft is journaled in a housing 9, and is indicated in Fig. 1 at 10, where a set-up is shown for internal grinding, comprising an arbor 11, supporting the shaft 10 and positioning the grinding wheel 12, correctly for the work desired. My base 1' has an angular extension 13, provided with ways 14. Co-operating ways 15 are formed upon the housing 9 of my grind shaft, and the housing is thus arranged to slide upon the angular extension 13, the motion thereof being controlled by a screw 16, journaled upon the extension as at 1'7, engaging a nut or threaded portion upon the housing 9, and provided with an operating handle, or the'like, 18.

As hereinabove indicated, the motion of the cross slide upon the tool carriage takes care of the horizontal component of the necessary adjusting motion of the grinder shaft 10. The vertical component of said motion is taken care of by the movement of the housing 9 along the ways 14 of the base extension 13. The necessary non-horizontal movement of the grind shaft is relatively slight. It has been pointed out that the member 13 and the ways thereon lie at an angle to the horizontal plane when the base member 1 is horizontal. I have shown at 19 a dotted line passing through the center of my grind shaft. This line is parallel to the ways 14, and consequently to the path of non-horizontal movement of my grind shaft. I have also shown at 20 a dotted arc, having as its center the center of the shaft 21 of my motor 5. A movement of my grind shaft along a path marked by this are, would result in no variation of tension in my belt 6. My grind shaft is shown in Fig. 2 in a position in which its center coincides exactly with a point at which the are 20 crosses the line 19. At an intermediate point 22 the are is displaced slightly upwardly from the line 19. At a further point 23, the are again coincides with the line. It will be seen that the present position of the center of my grind shaft, indicated at 24, is interspaced a considerable distance from the point 23, and that between these points, and even for a slight distance beyond them, the departure of the curve 20 from the line 19, is so very small as to be negligible so far as the tension of the belt 6 is concerned. A movement of my grind shaft from the position 24 and the position 23, or a placing of my grind shaft in any intermediate position, will thus be seen to have no practical effect upon the tension of my belt.

The above explanation will indicate the way in which I determine the angularity to the horizontal of the ways upon the extension 13. I first determine the degree of necessary movement of my grind shaft 10, for the desired centering or other adjustment. An are is struck: about my motor shaft 21 as a center, and the length of the desired movement of the grind shaft con structed as a chord to this are at a suitable position, or the desired movement may be laid oif on the arc, and a line which is a chord may be constructed to coincide with the are at the two points of extreme movement. It will be understood that these constructions are had about the normal or intermediate position of the grinder shaft, and the angularity of the said chord to the horizontal, or to the base of my grinder, will be the angle to which the ways 14 upon the member 13, are machined. In any instance in which a wider range of vmovement of the grinder shaft is desired, a further separation of the motor shaft from the grinder shaft will affect a flattening of the arc, whereby such wider movement may be accommodated. I have found that in ordinary situations, my method of construction enables me to provide inexpensive but adequate means for the movement and adjustment of the grinder shaft over the entire desirable range, without loss of the adjustment of the driving means.

Modifications may be made in my invention without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a device of the character described, an elongated base member provided near its mid length with means for mounting it on top of the cross slide of a lathe, an upstanding guide extension on said base member at one end thereof, a bearing member adjustable below the top of said base member and upwardly thereabove, on said extension, a driven shaft journaled in said bearing member, adapted to carry means to operate on work carried by the lathe spindle, a motor mounted on top of said base member near the other end thereof, with its shaft parallel with the driven shaft, the range of adjustment of said bearing member and the driven shaft journaled therein being generally below the horizontal plane of the motor shaft, and said guide extension guiding said bearing member and driven shaft in an inclined rectilinear path substantially at right angles to a plane in which the shaft axes lie when said driven shaft is midway 100 of its up and down adjustment, and a connection between said shafts, operative therebetween at various adjustments of the driven shaft.

2. In a device of the character described, a base member provided with means for mounting 195 on an element of a machine tool that is movable at an angle to the axis of a rotatable work holder of the machine tool, an upstanding guide extension on said base member, a bearing member adjustable up and down on said extension, a 110 driven shaft journaled in said bearing member, adapted to carry means to operate on work carried by the work holder of the machine tool, a motor mounted on said base member in spaced relation to said driven shaft, the range of adjust- 1 5 ment of said bearing member and driven shaft journaled therein being generally below the horizontal plane of the motor shaft, and said guide extension guiding said bearing member and driven shaft in an inclined rectilinear path substan- 129 tially at right angles to a plane in which the shaft axes lie when said driven shaft is midway of its up and down adjustment, and a connection between said shafts, operative therebetween at various adjustments of the driven shaft.

EMIL RITZ, JR. 

